The present human fear conditioning study examined whether the valence of an extinction cue has a differential effect on attenuating renewal that is induced by removal of the extinction context. Additionally, the study aimed to assess whether such attenuating effect is based on a modulatory or safety-signal role of the cue. In acquisition, extinction, and test stages of the experiment, human participants received pairings of human faces, presented against a particular background color, with the presence or absence of an aversive auditory stimulus. Experimental groups differed in the valence of a cue that was presented during extinction, in whether or not extinction took place against a different background color than present during acquisition and testing, and in whether the extinction cue was present or absent at test. The conditioned response consisted of auditory-stimulus expectancy ratings. It was hypothesized that a positively valued extinction cue yields faster extinction, stronger attenuation of renewal, and better transfer of its inhibitory power to non-extinguished stimuli than a negatively valued cue. All three hypotheses were confirmed, suggesting that the positive, but not the negative, cue had become a safety signal. The results were discussed in the framework of extinction-based exposure treatments.